Power sliding doors are a useful feature on minivans and the like. In some instances, however, the mechanisms that drive the movement of the sliding doors are unnecessarily large. In vehicles, and in vehicle doors in particular, it is advantageous to reduce the size of any components, such as the aforementioned drive mechanisms for moving the sliding doors.
The position sensors for such doors sometimes include a Hall effect sensor that acts as a rotation counter for the drive motor of the door. The Hall effect sensor is a relative position sensor however, and can only provide information regarding the position of the door relative to an initial position, based on the number of rotations of the drive motor that take place while moving the door. The rotation count may be stored in volatile memory. During operation of power sliding doors it can occur, however, that the door is stopped in a partially open position while power to the controller for the door is stopped. In such a situation, the rotation count from the sensor would no longer be stored in memory. As a result, when power is restored to the controller, the controller cannot establish the position of the door. It would be beneficial to provide a sensor that provides the absolute position of the door, so that the controller can determine the position of a partially open door after the power is returned to the controller.